package org.example.filter;

import jakarta.servlet.*;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.example.utils.JwtUtils;

import java.io.IOException;

//@WebFilter(urlPatterns = "/*")
@Slf4j
public class TokenFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1.获取到请求
        String requestURI = request.getRequestURI();

        //2.判断是否登录请求
        if (requestURI.contains("/login")) {
            log.info("登录请求，放行");
            filterChain.doFilter(request, response);
            return;
        }

        //3。获取请求头的token
        String token = request.getHeader("token");

        //4.判断token是否存在，如果不存在，说明用户没有登录，返回错误信息（响应401状态码）
        if (token == null || token.isEmpty()) {
            log.info("token不存在，用户未登录,令牌为空，响应401");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            return;
        }

        //5.如果token存在，校验令牌，如果校验失败 -> 返回错误信息（响应401状态码）
        try {
            JwtUtils.parseJWT(token);
        } catch (Exception e) {
            log.info("校验令牌失败，响应401");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            return;
        }

        //6.如果校验成功，放行
        log.info("校验令牌成功，放行");
        filterChain.doFilter(request, response);
    }
}
